This invention relates generally to electromagnetic detection apparatus and more particularly to apparatus for the detection of both infrared and radar energy.
The desirability of combining an infrared detection system and a radar detection system is well known. In particular, such combined systems are extremely useful when employed in a semi-active air-to-air missile. Such a missile is operated in conjunction with a remote radar transmitter, as a target tracking radar carried by a missile launching aircraft. A combined infrared and radar detection system permits the radar system to be employed for long range target engagements and the infrared system to be employed at short range or "dog fight" engagements where it is difficult for the missile launching aircraft to provide proper radar illumination of the target.
Attempts to combine both an infrared detection system and a radar detection system have resulted in the use of a reflective radar antenna in combination with a reflective infrared optical configuration. Such combined reflective configurations have the disadvantage of requiring separate infrared-radar reflective surfaces, each such reflective surface being of different curvature and material so as to thereby properly focus the radar energy and the infrared energy to their respective detection elements.